This invention relates to cable preparation tools, specifically to an improved tool and an accompanying method which, when utilized concurrently, prepare fully shielded cables for termination into connecting devices.
Improvements in telecommunications systems have resulted in the ability to transmit voice and/or data signals along transmission lines at increasingly higher frequencies. Several industry standards specify that multiple performance levels of twisted-pair cabling components have been established. The primary references, considered by many to be the international benchmarks for commercially based telecommunications components and installations, are standards ANSI/TIA/EIA-568-A (/568), Commercial Building Telecommunications Cabling Standard, and 150/IEC 11801 (/11801), Generic Cabling for Customer Premises.
Standards /568 and /11801, as well as other existing national and regional standards, specify use of category 3, 4 and 5 cable and connecting hardware. In these specifications, transmission requirements for Category 3 components are specified up to 16 MHZ. Transmission requirements for Category 4 components are specified up to 20 MHZ. Transmission requirements for Category 5 components are specified up to 100 MHZ.
New standards are being developed continuously and currently it is expected that future standards will require transmission requirements of at least 600 MHZ. To achieve such transmission rates, fully shielded twisted pair cable, as shown generally at 10 in FIG. 1, will be necessary. Such cable contains individual insulated wires 16 that are paired with each pair being wrapped in a metallic foil 18. Then the pairs are wrapped together in another layer of foil or screen 14, and finally bound within an insulative jacket 12.
The above referenced transmission requirements also specify limits on near-end crosstalk (NEXT). Telecommunications connectors are organized in sets of pairs, typically made up of a tip and ring connector. As telecommunications connectors are reduced in size, pairs are placed closer to each other creating NEXT between adjacent pairs.
To comply with the NEXT requirements, a variety of techniques are used in the art. U.S. patent application Ser. No. 09/470,046, incorporated herein by reference, describes an enhanced performance telecommunications connector, appearing generally at 20 in FIG.2, which utilizes overlapping shield members to provide enhanced shielding and reduced crosstalk in the mating of fully shielded cable connectors.
FIG. 3 depicts an exemplary process for installing a cable 10 in a connector 20. The cable is first prepared as shown in FIG. 4. A length (shown as A) of the cable jacket 12 is removed. Then, a second length (shown as B) of the metallic foil 18 is removed. As shown in FIG. 3, the individual wires 16 are aligned and then inserted into termination caps 22. The termination caps 22 are then clamped down to terminate wires 16 on insulation displacement contacts in connector 20.
Traditional methods of preparing fully shielded cable for connector installation require the installer to take measurements by hand, execute multiple stripping actions using several tools, including sharp blades, and arrange wires 16 by hand for insertion into connector. Distances A and B are typically hand measured by the installer. Conventional cable preparation tools, such as that illustrated in FIG. 5 or that produced by Sargent Tool Company, commercially available as xe2x80x988700 Easy Strip Compress Toolxe2x80x99, can be used to remove cable jacket 12. Such conventional tools, however, fail to assist the installer in removing foils 18 and aligning inner wires for insertion into connector. A straight blade, such as a knife or scissors, is traditionally used to individually remove metallic foil 18. Then the installer must visually align wires 16 by hand for insertion into termination caps 22.
Prior art methods of cable preparation involve several tools, multiple steps and result in considerable installation time. Removal of metallic foil 18 by use of an open blade exposes the installer to safety hazards and threatens the severance of individual insulated wires 16. Once wires 16 are exposed, the cable must be installed in the connector. Manual arrangement of wires 16 is time consuming and subject to installer error. If the wires are inserted improperly into the connector, the connector will fail to function properly and additional time and resources will be consumed in making the appropriate corrections. Hence, the need has arisen for an invention which allows a fast, simple, and safe method of preparing fully shielded cable for connector termination by use of one, low-cost tool.
The above-discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by the cable preparation tool and cable preparation method of the present invention. The cable preparation tool is designed for use with shielded cable including a plurality of pairs of wires, each pair of wires surrounded by a metallic foil. The tool includes first and second tool handles, a blade assembly, and a template assembly provided in one of said first and second tool handles. A method of preparing the shielded cable includes inserting the cable in a cutting portion of the tool and cutting the cable jacket using the tool. The outer cable jacket is removed and the pairs of wires are placed in the cutting portion of the tool. Each of the foils is cut in one step using the tool.